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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Uwe Zeisbergerf30c2262006-10-03 23:01:26 +02002 * include/linux/writeback.h
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 */
4#ifndef WRITEBACK_H
5#define WRITEBACK_H
6
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +04007#include <linux/sched.h>
Jens Axboef5ff8422007-09-21 09:19:54 +02008#include <linux/fs.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +04009
Linus Torvalds1da177e2005-04-16 15:20:36 -070010struct backing_dev_info;
11
12extern spinlock_t inode_lock;
13extern struct list_head inode_in_use;
14extern struct list_head inode_unused;
15
16/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 * fs/fs-writeback.c
18 */
19enum writeback_sync_modes {
20 WB_SYNC_NONE, /* Don't wait on anything */
21 WB_SYNC_ALL, /* Wait on every mapping */
Linus Torvalds1da177e2005-04-16 15:20:36 -070022};
23
24/*
25 * A control structure which tells the writeback code what to do. These are
26 * always on the stack, and hence need no locking. They are always initialised
27 * in a manner such that unspecified fields are set to zero.
28 */
29struct writeback_control {
30 struct backing_dev_info *bdi; /* If !NULL, only write back this
31 queue */
Jens Axboe03ba3782009-09-09 09:08:54 +020032 struct super_block *sb; /* if !NULL, only write inodes from
33 this super_block */
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 enum writeback_sync_modes sync_mode;
35 unsigned long *older_than_this; /* If !NULL, only write back inodes
36 older than this */
Edward Shishkinf11c9c52010-03-11 14:09:47 -080037 unsigned long wb_start; /* Time writeback_inodes_wb was
38 called. This is needed to avoid
39 extra jobs and livelock */
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 long nr_to_write; /* Write this many pages, and decrement
41 this for each page written */
42 long pages_skipped; /* Pages which were not written */
43
44 /*
45 * For a_ops->writepages(): is start or end are non-zero then this is
46 * a hint that the filesystem need only write out the pages inside that
47 * byterange. The byte at `end' is included in the writeout request.
48 */
OGAWA Hirofumi111ebb62006-06-23 02:03:26 -070049 loff_t range_start;
50 loff_t range_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Andrew Morton22905f72005-11-16 15:07:01 -080052 unsigned nonblocking:1; /* Don't get stuck on request queues */
53 unsigned encountered_congestion:1; /* An output: a queue is full */
54 unsigned for_kupdate:1; /* A kupdate writeback */
Wu Fengguangb17621f2009-12-03 13:54:25 +010055 unsigned for_background:1; /* A background writeback */
Andrew Morton22905f72005-11-16 15:07:01 -080056 unsigned for_reclaim:1; /* Invoked from the page allocator */
OGAWA Hirofumi111ebb62006-06-23 02:03:26 -070057 unsigned range_cyclic:1; /* range_start is cyclic */
Fengguang Wu8bc3be22008-02-04 22:29:36 -080058 unsigned more_io:1; /* more io to be dispatched */
Aneesh Kumar K.V17bc6c32008-10-16 10:09:17 -040059 /*
60 * write_cache_pages() won't update wbc->nr_to_write and
61 * mapping->writeback_index if no_nrwrite_index_update
62 * is set. write_cache_pages() may write more than we
63 * requested and we want to make sure nr_to_write and
64 * writeback_index are updated in a consistent manner
65 * so we use a single control to update them
66 */
67 unsigned no_nrwrite_index_update:1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070068};
69
70/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 * fs/fs-writeback.c
72 */
Jens Axboe03ba3782009-09-09 09:08:54 +020073struct bdi_writeback;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074int inode_wait(void *);
Jens Axboeb6e51312009-09-16 15:13:54 +020075void writeback_inodes_sb(struct super_block *);
Eric Sandeen17bd55d2009-12-23 07:57:07 -050076int writeback_inodes_sb_if_idle(struct super_block *);
Jens Axboeb6e51312009-09-16 15:13:54 +020077void sync_inodes_sb(struct super_block *);
Jens Axboe03ba3782009-09-09 09:08:54 +020078void writeback_inodes_wbc(struct writeback_control *wbc);
79long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
80void wakeup_flusher_threads(long nr_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82/* writeback.h requires fs.h; it, too, is not included from here. */
83static inline void wait_on_inode(struct inode *inode)
84{
85 might_sleep();
Christoph Hellwigeaff8072009-12-17 14:25:01 +010086 wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087}
Joern Engel1c0eeaf2007-10-16 23:30:44 -070088static inline void inode_sync_wait(struct inode *inode)
89{
90 might_sleep();
91 wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
92 TASK_UNINTERRUPTIBLE);
93}
94
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96/*
97 * mm/page-writeback.c
98 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070099void laptop_io_completion(void);
100void laptop_sync_completion(void);
Andrew Morton232ea4d2007-02-28 20:13:21 -0800101void throttle_vm_writeout(gfp_t gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
103/* These are exported to sysctl. */
104extern int dirty_background_ratio;
David Rientjes2da02992009-01-06 14:39:31 -0800105extern unsigned long dirty_background_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106extern int vm_dirty_ratio;
David Rientjes2da02992009-01-06 14:39:31 -0800107extern unsigned long vm_dirty_bytes;
Alexey Dobriyan704503d2009-03-31 15:23:18 -0700108extern unsigned int dirty_writeback_interval;
109extern unsigned int dirty_expire_interval;
Bron Gondwana195cf4532008-02-04 22:29:20 -0800110extern int vm_highmem_is_dirtyable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111extern int block_dump;
112extern int laptop_mode;
113
Steven Rostedt3eefae92008-05-12 21:21:04 +0200114extern unsigned long determine_dirtyable_memory(void);
115
David Rientjes2da02992009-01-06 14:39:31 -0800116extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700117 void __user *buffer, size_t *lenp,
David Rientjes2da02992009-01-06 14:39:31 -0800118 loff_t *ppos);
119extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700120 void __user *buffer, size_t *lenp,
David Rientjes2da02992009-01-06 14:39:31 -0800121 loff_t *ppos);
Peter Zijlstra04fbfdc2007-10-16 23:25:50 -0700122extern int dirty_ratio_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700123 void __user *buffer, size_t *lenp,
Peter Zijlstra04fbfdc2007-10-16 23:25:50 -0700124 loff_t *ppos);
David Rientjes2da02992009-01-06 14:39:31 -0800125extern int dirty_bytes_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700126 void __user *buffer, size_t *lenp,
David Rientjes2da02992009-01-06 14:39:31 -0800127 loff_t *ppos);
Peter Zijlstra04fbfdc2007-10-16 23:25:50 -0700128
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129struct ctl_table;
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700130int dirty_writeback_centisecs_handler(struct ctl_table *, int,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 void __user *, size_t *, loff_t *);
132
David Rientjes364aeb22009-01-06 14:39:29 -0800133void get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty,
134 unsigned long *pbdi_dirty, struct backing_dev_info *bdi);
Peter Zijlstracf0ca9f2008-04-30 00:54:32 -0700135
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136void page_writeback_init(void);
Andrew Mortonfa5a7342006-03-24 03:18:10 -0800137void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
138 unsigned long nr_pages_dirtied);
139
140static inline void
141balance_dirty_pages_ratelimited(struct address_space *mapping)
142{
143 balance_dirty_pages_ratelimited_nr(mapping, 1);
144}
145
Miklos Szeredi0ea97182007-05-10 22:22:51 -0700146typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
147 void *data);
148
Miklos Szeredi0ea97182007-05-10 22:22:51 -0700149int generic_writepages(struct address_space *mapping,
150 struct writeback_control *wbc);
151int write_cache_pages(struct address_space *mapping,
152 struct writeback_control *wbc, writepage_t writepage,
153 void *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
Peter Zijlstraa200ee12007-10-08 18:54:37 +0200155void set_page_dirty_balance(struct page *page, int page_mkwrite);
Chandra Seetharaman2d1d43f2006-09-29 02:01:25 -0700156void writeback_set_ratelimit(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
158/* pdflush.c */
159extern int nr_pdflush_threads; /* Global so it can be exported to sysctl
160 read-only. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162
163#endif /* WRITEBACK_H */